Voyager 1 is approaching a historic milestone that will place it one light-day from Earth on Wednesday, November 18, 2026, while NASA engineers continue managing the spacecraft’s shrinking power supply and intermittent technical problems.
At 2:16:07 a.m. Pacific time on November 18, Voyager 1 is expected to be about 16.094 billion miles, or 25.902 billion kilometres, from Earth.
That is the distance light travels in 24 hours.
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Voyager 1 is nearing a 24-hour signal delay
Once the spacecraft reaches that distance, a radio signal sent from Earth will take roughly one day to arrive.
A response from Voyager 1 will require another day to return, creating a round-trip communication delay of about 48 hours.
The milestone will not trigger a change aboard the spacecraft or alter its environment.
Its significance is symbolic and scientific: Voyager 1 will become the first human-made object to reach a distance of one light-day from Earth.
NASA says Voyager 1 is travelling at approximately 38,000 miles per hour, or 61,155 kilometres per hour.
It remains the most distant human-made object in existence.
NASA recently restored contact with Voyager 1
The milestone comes after a brief communications interruption in October.
NASA’s Deep Space Network failed to detect Voyager 1’s radio signal during two scheduled attempts on October 18 and 19.
The signal returned on October 20, and engineers have maintained contact since then.
NASA said the spacecraft’s fault-protection system had detected a problem involving one group of thrusters, switched to backup thrusters and placed the probe in a stable configuration.
Engineers are still investigating what caused the automatic switch.
The spacecraft’s extreme distance means that commands and diagnostic information move slowly between Earth and Voyager 1.
A power-saving manoeuvre is extending the mission
In September, NASA completed a months-long power-conservation operation known as the “Big Bang.”
Engineers switched off three devices and replaced them with three lower-power alternatives.
The devices help distribute heat through the spacecraft, which operates in the extremely cold environment beyond the heliosphere.
NASA said the coordinated replacement reduced energy use while maintaining the thermal conditions needed for continued operation.
Voyager 1 is powered by radioisotope thermoelectric generators that convert heat from decaying plutonium into electricity.
The ageing power system loses about four watts of available power each year.
Without the latest power-saving work, NASA said the mission might have needed to switch off another scientific instrument as early as summer 2027.
The manoeuvre is expected to allow Voyager 1’s remaining science instruments to operate longer than previously anticipated.
Only two science instruments remain active
Voyager 1 launched on September 5, 1977, with 10 dedicated science instruments.
Several were shut down after the spacecraft completed its planetary encounters, while others were later disabled because of declining performance or limited power.
NASA’s current instrument status lists Voyager 1’s magnetometer and plasma wave subsystem as operating.
Its cosmic ray subsystem was turned off in February 2025, and its low-energy charged-particle instrument was switched off in April 2026 to conserve power.
The spacecraft’s cameras have been inactive for decades.
Voyager 1’s mission now focuses on measuring conditions in interstellar space rather than photographing planets.
Voyager 1 remains in interstellar space
Voyager 1 crossed the boundary of the heliosphere in August 2012, according to NASA.
The heliosphere is the protective bubble of particles and magnetic fields generated by the Sun.
Voyager 1 and Voyager 2 are the only spacecraft to have directly operated outside that region.
Their measurements continue to help scientists study the environment between stars.
The spacecraft originally was designed for a planetary mission and conducted close encounters with Jupiter and Saturn.
Its extended mission has lasted for decades beyond its original objectives.
What happens after the November milestone
Voyager 1 will continue moving outward after reaching one light-day from Earth, although its scientific capabilities will gradually decline as its power supply weakens.
NASA’s Voyager team is expected to continue switching off non-essential systems and instruments when necessary.
The mission’s future will depend on available power, thermal conditions, communications performance and the health of its ageing computer and propulsion systems.
For now, NASA says Voyager 1 remains in communication with Earth and is continuing its journey through interstellar space.
Frequently Asked Questions
When will Voyager 1 reach one light-day from Earth?
NASA expects Voyager 1 to reach one light-day from Earth on Wednesday, November 18, 2026, at 2:16:07 a.m. Pacific time.
How far away is Voyager 1?
At the November 18 milestone, Voyager 1 is expected to be 16.094 billion miles, or 25.902 billion kilometres, from Earth.
How long does a signal take to reach Voyager 1?
At one light-day, a radio signal takes about 24 hours to travel one way between Earth and Voyager 1, making a round trip roughly 48 hours.
Is Voyager 1 still operating?
Yes. Voyager 1 remains in communication with NASA and continues its extended mission in interstellar space, although many instruments and systems have been turned off to conserve power.
What instruments are still operating on Voyager 1?
NASA currently lists Voyager 1’s magnetometer and plasma wave subsystem as operating.
Fact-Checked: Key dates, distances, communications updates, power-conservation measures and instrument statuses were checked against NASA and NASA Jet Propulsion Laboratory information.
Disclaimer: Voyager 1’s projected milestone time and spacecraft status may be revised if NASA receives new telemetry or updates its mission calculations.